What do you know about Niger? It is one of the hottest countries in the world.
In the capital, Niamey, temperatures regularly climb above 40°C during the hottest months, while the Sahel region around it is warming faster than the global average. The heat can be punishing during the day. Even the nights offer less relief. This is because heat can linger for hours at night.
A new Climate Central analysis says warmer nights are costing people sleep in Niamey. People sleep less in Niamey than in any other country in Africa because of the heat.
Researchers examined nighttime temperatures in 1,338 cities worldwide, comparing conditions in the early 1970s with those between 2020 and 2025. They estimate that people in 140 African cities now lose an average of about 64 hours of sleep each year because of warm nights. Climate change accounts for about seven of those hours.
The change has been rapid. In the early 1970s, climate change was estimated to contribute about 2.6 hours of sleep loss each year in the African cities studied. Today, that figure has risen to about 6.7 hours.
The burden is particularly noticeable in some of Africa’s hottest cities. In Niamey and Sokoto, Nigeria, climate change has added roughly 10 to 11 hours of lost sleep each year. People in these places were already accustomed to hot nights, but rising temperatures are making it harder for nighttime conditions to provide relief.
“People in some cities across West Africa, including selected cities in Niger, Nigeria, and Burkina Faso, lost 65 hours of sleep or more per year, including about 10 to 11 hours linked to climate change,” authors wrote.
In other cities, the change is for a different reason. Nairobi and Nakuru in Kenya and Addis Ababa in Ethiopia traditionally experienced cooler nights. As temperatures rise, climate change now accounts for more than a fifth of their heat-related sleep loss, according to the analysis.
The hottest coastal and equatorial cities face an even larger overall problem. In places such as Djibouti, Cotonou in Benin and Conakry in Guinea, people can lose more than 90 hours of sleep a year because of nighttime heat. Climate change is only part of that total, but it is adding to an already difficult climate.
The consequences go beyond waking up tired. Repeated sleep disruption can affect health, concentration, productivity and quality of life. Unlike a flood or drought, a hot night may pass without attracting much attention. But when it happens night after night, the cost begins to accumulate.
Source: Climate Central, “Climate Change is Costing People Sleep,” July 15, 2026. The analysis compared 1970–1975 with 2020–2025 across 1,338 cities.